Fuse clip clamp



Sept. 6, 1960 L. DETCH FUSE CLIP CLAMP Filed Dec. 19, 1957 United States Patent C) The rr s nt nvea a lat se l nt and re er mor Par u o c amps, o bui t: up construcon! 'Euse clips which have. had long service, lose some oftheir resiliency due to repeated heating and cooling. The. clips may also be spread too far apart bynegligent forcing "ice tern inating short of its top and bottom. Air circulating in this recess oqols both the pad and outer flap and increa es he c oling c p ci y of the mp- Iihe invention accordingly consists in the features of n, combinations of elements and arrangements of partswhich. will be exemplified in the constructions hereinafter descrbed. Inthe accompanying drawing, in which are shown three of the various possible illustrative embodiments of this invention:

F ,e; 1 a perspective view of the invention embod ed in. a clamp for a fer-rule type fuse, showing also the fuse clip and showing the fuse and block in fragment. Figure {Ziis a central vertical. section through the clip and clamp, ofl igure 1,. showing the, fuse in end elevation. Figure}; acorresponding view of a modified form of "the, invention.

of the fuse too far down inthe clip. Poo-r mechanical contact between fuse and clip, results in poor electrical conductivity between the two and causes the fuse to. heatunduly and blow prematurely. Fuse clips are frequently very inconvenient to replace and consequently whole panels or boxes are replaced at substantial cost,

An object of the present invention is to provide a fuse. clip clamp. which may be applied over old or new clips bythe fingers of an operator.

Another object is to provide a clamp having superior. reinforcing action. v

A further object is to provide a clamp. having subst-antialheat sucking and heat dissipating properties, so, that the fuse may operate for a longer Fume under condi-.. tions close to its calculated rating.

In accomplishing the objects of the present invention a fuse clip clamp is provided having a short inner flap and .a longer outer =flap located on each side of the clip; the flaps on each side of the clip being integral withf'a; bottom member and forming therewith, a J, shapein cross:

s c ion, the o r fl p being n cted oge he n a t s ans la f mati n by sverse. bars. ex ending f om one side to the other of theclip, and the. flaps. and. bars, being unitary, preferably being' stamped from a single sheet of metal. So much of the new construction is known. be n di c osed, my cont d ng app Serial No. 549,390, filed November28, l 9 5 5,t and now abandoned.

The abov escribed construction th inforced mseh ui a v d deredm re. a sorpt v of heat y a h a r padloq ted ins de the J to an' in each de l pt. This had sp e erah y at least qua n he sh a d W h. 0 th out r flap d s' exceed the latter in height, and in case the outer flap is curved the pad is correspondingly curved. The pad is preferably riveted to the outer flap. The pad, being in contact with the clip draws heat therefrom and both the clip and fuse are thus cooled and rendered more uniform in operation. Due to the cooling, over a given period of time fewer fuses will blow and the clip is thus subjected to fewer cycles of heating and cooling and the life of the clip is thus prolonged.

In a modified form of the invention, each pad is provided at its top inside surface with a smaller pad of less conductive material such as steel. As the clip and clamp are alternative electrical paths for the current, the steel being less conductive will cause more current to flow through the clip. The pad thus carrying a smaller current will be less heated and will be able to draw more heat from the clip and fuse.

In another modified form of the inventiomthe pad is formed with a recess extending across its length and Figure 4 isv acorresponding view of a clip and clamp only of another modified formof the invention.

Referring now in detail to. Figures 1 and 2, a fuse block 10 has mountedthereon .a fuse clip 11 for a ferrule type fuse 12, all of the above being conventional. The clamp 13 has a chassis 14, which is a unitary body, preferably a. stamping of Phosphor-bronze spring sheet.

Chassis. .14 has theside rails 15 and end rails 16 defining a rectangular opening 17. through which the arms 11A,

of the clip 11 may pass. Integral with side rails 15 are the upstanding inner flaps 18 and longer outer flaps 19, also upstanding, the flaps 18, 19 extending substantially the full length of the side rails, 15. The two flaps 18, 1 9; integral with a side rail 15' thus form with said rail a J shape. The flaps 18, 19) are resilient and bear inwardly against the arms 11A of the clip 11, the flaps 18 being in contact with the arms 11A and the flaps 19 hearing against the arms 11A through the pads 20.

Said pads 20 are relatively thick blocks of metal, preferably a high thermalconductive metal such as copper The pads 20 are located between the flaps 18, 19, extending the full length of the flaps, and also extending from the side rails 15 to above the flaps 19, and further being curved so as to contact near their tops the arms 11A of the clip 11. Rivets 21 hold the pads 20 in contact with the flaps 19 and the thermal conductive relation of pad and flap may be enhanced by solder 22 uniting the two.

In operation, the clamp 13 may be easily pushed down over an empty clip 11 by the fingers of an operator, the clip entering the opening 17 as the clamp passes down- Wardly. The relation of clamp and clip will then be approximately as illustrated in Figures 1 and 2 except that the clamp will fit loosely on the clip. When the fuse 12 is then forced into the clip the latter will be dis tended as illustrated. The high thermal conductive pads 20 are-now in contact with the arms =11A, being resiliently maintained in such contact by the outer flaps 19. The inner flaps 18 are also in contact with arms 11A and with the pads 20. From the above it will be observed that the resilient fiaps 18, 19 have to a limited extent gone solid with the massive interposed pads 20, forming thereby a large heat reservoir which will draw heat from the clip 11 and fuse 12 as the latter produces heat on moderate overload. It is important to remember however that some resilience remains in the structure. For instance, a small upwardly diminishing tapered space 23 remains between arms 11A and the lower part of the inner flaps 18. Even in the absence of such space, the flaps 18 can slide on pads 20 and pads 20 can move relative to rails 15 albeit slightly, so that the clamp retains adaptability to clips and fuses of slightly differing dimensions such as result from design differences and manufacturing tolerances. The solder 22 is optional, the use thereof increasing heat transfer from pad 20 to flap 19 for more efiicient dissipation to the surrounding air, while neutralizing the resilient properties of so much of flap 19 as is united to the massive pad 20. In-the absence of solder a less efficient heat transfer is bad and the full resilience of flap 19 is retained.

A further advantage of the within invention is that the heat sucking pads 20 are interposed between the flaps 18, 19 so as almost to fill the space therebetween and when the clamp is in operation the short inner flaps 18 bear against pads 20 and the latter bear against flaps 19 so that the resilient force of flaps 19 is in part added to the flaps 18 in their important function of reinforcin the base portions of the arms 11A.

In Figure 3 is illustrated a clamp 30 identical to clamp ventilating recesses 60 extending throughout their length and t'erminatingshort 'of'the top and bottom of said pads 58. As the recesses 60-are thus open to the atmosphere at each end of the clamp, as the pads 58 draw heat from the clip 50 the air in the recesses will become heated and will escape being replaced by cooler air, and the circulation of air thus produced will cool clamp 51 and enable it to draw more heat from clip 50.

It will thus be seenthat there is provided a device in which the several objects of this invention are achieved, and which is well adapted to meet the conditions of, practical use. 7 As various possible embodiments might be made of the above invention, and as various changes 13 except as noted hereafter. Clamp 30 has no solder.

between the outer flaps 39 and pad 40, the two being connected merely by the rivet 41. A small tapered space 42 exists between the bottom of pad 40 and flap 39. The absence of a similar space between inner flaps 38 and pad 40 should be considered as illustrative of the different fit between clamps of identical dimensions on clips and fuses of slightly different dimensions, rather than as illustrating a difference in function of the clamp. It has been noted in respect of clamp 13, Figures 1 and 2, that the flaps still retain the ability to move relative to the rail and that the inner flap may still slide on the pad. It is additionally true in clamp 30 that flaps 39 retain their full resiliency. Therefore clamp 30 despite an apparent difierence in the illustration is effective like clamp 13 to reinforce the short inner flaps 38 with the resilient action of the outer flaps 39 acting over the interposed pads 44).

The pads 46 are of high thermal-conductive metal such as copper, and have small pads 42 extending along their length at their top, the pads 42 being of steel or some metal of comparatively low electrical conductivity. The pads 42 thus constitute an electrical resistance which might be made in the embodiments above set forth, it is to be understood that all matter herein set forth or shown in the accompanying drawing is to be interpreted as illustrative and not in a limiting sense.

What is claimed is:

*1. A fuse clip clamp comprising, in combination, side rails and end rails connected together and defining a rectangular opening for a fuse clip, each side rail having integral therewith aresilient inner flap and a resilient outer flap, said flaps extending upwardly from each side rail, said inner flaps in operation being adapted to resilientlybear inwardly-against the fuse clip, and a relatively thick pad of metal located between each inner fiap "and the respective outer flap and maintained in contactrwith the clip by the respective outer .flap, each pad and its respective outer flap thereby constituting a heat will limit the flow of current through pads and cause the current to flow rather through the clip 31. As the clip 31 was designed to carry the full current, the re sistance in pads 42 will not produce any substantial heat. However as the current has been confined substantially entirely to clip 31, the clamp 30 will remain cooler than if it had carried a current, and will thus be able to draw more heat from the clip 31 and fuse 32.

In Figure 4 is illustrated another modified form of the invention. A clip 50 fora knife blade fuse, not shown, is loosely engaged by the'clamp 51, the looseness of the engagement being due to the absence of the fuse. Clamp 51 comprises a chassis 52 which is a unitary body comprising side rails 53, end rails 54, and inner flaps 5S and outer rails 56 extending upwardly from side rails 53 and constituting with the latter a J shape. The side and end rails define a rectangular opening 57 by means of which the clamp is applied to the clip from above. The relatively heavy pads 58 extend the length of the side rails 53, as do the inner and outer flaps 55, 56. The pads 58 are of high thermal conductive metal such as copper, and are in contact with the clip 50 and with the outer flaps 56, further being connected to the latter by the rivets 59. Pads 58 are formed with the reservoir to draw heat from the fuse clip while reinforcing the same mechanically.

'2. In a clamp for a fuse clip, a chassis of unitary construction comprising side and end rails connected together and defining a substantially rectangular opening for a fuse clip, each side rail comprising integrally an inner resilient flap and an outer resilient flap, said flaps extending upwardly from said rail, said inner flaps in operation being adapted to bear inwardly against the fuse clip, and a comparativelythick pad of metal located between each inner flap and the respective outer flap,v and adapted. to be maintained in resilient contact with the fuse clip by said adjacent outer flap, to thereby draw heat from the fuse clip, said pad further substantially filling the space between the respective adjacent inner and outer flaps and adding part of the resilient force of the respective outer flap to the respective inner fiap in the bearing of the latter against the fuse clip.

References Cited in the file of this patent UNITED STATES PATENTS 1,836,890 Young Dec. 15, 1931 1,886,758 Swars Nov. 8, 1932 2,353,286 Bender July 11, 1944 2,415,404 Baller Feb. 11, 1947 2,808,576 Brown Oct. 1, 1957 FOREIGN PATENTS 343,468 Great Britain 1 Feb. 18,1931 

